Casing head



Oct. 25, 1932.

1 4/ 'f/x I ATTORNEY Patented Oct. 25, 1932 ALEXANDER BOYN TON, OF SAN ANTONIO, TEXAS CASING HEAD Application filed December 6, 1927. Serial No. 238,132.

This invention relates to' improvements in casing heads for oil wells, and it consists of the constructions, combinations and arrangements herein described and claimed.

An object of the invention is to provide a casing head for oil wells and the like, special provision being made for preventing the escape of pressure fluid used Within the Well casing, the foremost ones of several modifications employing the principle of expanding a portion of the tubing carrier to force the male threads into sealing-off engagement with the female threads.

Other objects and advantages appear in the following specification, reference being had to the accompanying drawing, in which;

Figure 1 is a vertical section of a casing head illustrating one of the foremost forms of the invention,

Fig. 2 is a fragmentary sectional view illustrating a modification wherein a double edged annular wedge is employed,

Fig. 3' is a fragmentary sectional view illustrating an inversion of thearrangement in Fig. 1,

Fig. 4 is a fragmentary sectional view demonstrating the employment of a familiar mode of casting an annular ring of dissimilar material in operative position, as described more in detail later on.

This casing head is designed to withstand high fluid pressures customarily employed within the well casing for the purpose of lifting the liquid therein. An incident to the employment of such high pressures is the development of suitable packing arrangement rendering the joints between parts of the casing head immune against mechanical failure.

Various expedient's may be followed to achieve the ultimate purpose, but several of the important modifications now disclosed propose the distortion, spreading or expansion of part of the metal composing the tubing carrier so that there may be a tight binding between this part with the main body of the casing head. In Fig. 1, the main body of the casing head is indicated 1. The tubing carrier 2 has adjoining sections of the tubing string 3 screwed into the extremities tioned. It is evident that an extremely tight vof a bore 4. The extremity of the tubing carrier is reduced in size, but in-practice is round or hexagonal at 5 to facilitate the application and use of wrench or tongs in screwing the tubing carrier in and out. The male threads of the tubing. carrier engage the female threads of the main body 1 at 6; It is observed that the enlarged upper portion 7 of the main body constitutes part of thethickenedbase 8 of the main body. The base 8 has an'integral upstanding annular tongue 9 of wedgesshape. A groove 10 in the carrier 2 has a narrow prolongation I 17 rendering the resulting rim portion or Wall 11 desirably flexible. The tongue, 9 fits into the annular groove 10 in such manner as to force the male threads of the carrier 2 into sealing ofl engagement with the adjoining female threads of the portion 7 by expanding the flexible lower rim portion 11 of the carrier 2 as the latter is screwed downward.

The foregoing desired action, is brought about by the engagement of the variously inclined surfaces of the tongue and groove, the inclinations of these surfaces being such that the contact at 12 between the tongue 9 and groove 10 is such as to produce an outward thrust of the. rim 11 in the direction menengagement of the threads may be obtained, and With this form of the invention, it is not essential that extra packing be employed. An annular groove 18 in the tubing carrier 2, situated intermediately of the bore 4 and groove 10'17, produces a second flexible wall 19 which exercises a function like that of the wall 11. The groove 18 produces a concavity upon the walls of which the internal fluid pressure exercises pressure, and in doing so produces a seal-off of the wall 19 against the tongue 9 at the point 20. Figure 2 exemplifies the foregoing principle by a slightly difierent structure. All similar parts are identified by corresponding reference numerals. vThe base 8 is now formed with an annular groove 13 in which the annular wedge-rin 14 accurately fits. This wedge ring is pre erably composed of bronze but may be of any other suitable material.

It is apparent that screwing down of the tubing carrier 2 will cause such engagement of the exposed portion of the wedge-ring with the surfaces of the groove 10 that the rim 11 becomes distorted or expanded. This has the same effect in respect to the screw threads as in the instance of Fig. 1. An advantage of the arrangement in Fig. 2 is that the ring or wedge 14 is renewable should long use result in any damage tonthe important exposed edges and surfaces.

In Fig. 3 the annular wedge-shaped tongue 9 is formed on the lower side of the tubing carrier 2 and arranged for engagement with is thrust into the aforesaid sealing-off engagement as the annular wedge or tongue 9 is forced down upon it by screwing the tubing carrier 2 into the enlarged upper portion 7.

Figure 4 discloses another variation of the sealing-off means. The annular ring 14 (following the arrangement in Fig. 2), is originally cast into the dove-tailed or other groove 13 in the-base 8, the anchorage of the ring being ultimately assured by peening the adjoining surfaces of the base. This peening will not be necessary, however, if suflicient bevel be given to base 13 of ring 14. The upper portions of the ring 14 are rounded at 15 and are engaged at points 16 with the rounded groove 90 in the tubing carrier 2.

The operation of the arrangement in Fig. 4

tends to have the same effect as the arrangement in Fig. 1.

Reverting to the modifications in Figs. 1

p and 2, it may be emphasized that two forces act upon the flange 19 to maintain a fluidtight 'oint at the point 20. These forces act entirely independent of each other. The beveled slope of the annular tongue 9 tends to sure is exerted to effect a tight joint at the tongue and thus prevent the escape of pressure fluid.

2. A casing head having a main body with a tongue having a beveled surface, a carrier, and screw threads by which the carrier is secured to the body, said carrier having concentric grooves defining a flexible wall said tongue being received by one of the grooves so that a portion of the wall bears against the beveled surface at which tight contact is made by reaction of the screw threads, the other groove being subject to internal fluid pressure to press the wall against said tongue at said point of contact.

3. A main body comprising part of a pressure fluid container and having a wall, a tubing carrier fitted in the body and having concentric grooves of which one is accessible by the pressure fluid, an annular wedge carried by the body for occupancy in another groove, and means forcing the carrier down on the wedge to flex an outer annular part against the wall and flex an annular portion between grooves in a direction in opposition to the fluid pressure thereagainst.

Signed at San Antonio, in the county of Bexar and State of Texas, this 25th day of October, A. D. 1927.

ALEXANDER BOYNTON.

press the flange 19 inwardly wherf the tubing carrier 2 is screwed down thereby producing a spring action contact at the aforementioned point 20. The tension set up in the flange 19 by virtue of said spring action represents one of the forces in mind. The second force is represented by,the expanding action of the internal fluid (gas or air) pressure within the annular recess 18. This dual force of the downward pressure exerted by the threads and the expansive force of the internal fluid pressure combine to maintain the desired tight joint mentioned before.

I claim 1. A casing head internally subject to pres- 

